Prior to provisioning a circuit through a network (e.g., telecommunications network, data network, etc.) for a given service, a route must be determined between the desired start and end points. To determine this route, the network is typically modeled as a graph of links and nodes where each link is assigned a cost. Based on the costs, a least cost/shortest path routing algorithm, such as Dijkstra's algorithm, is used to dynamically find a shortest/least cost route between two of the end-points specified by a user. The new circuit is then provisioned over this determined route for the service.
To determine the link costs, an administrator of the network analyzes the different technologies and characteristics of the network links and makes a pre-determination as to the importance of each characteristic, giving some greater importance than others. Based on this analysis, the administrator assigns each link a cost giving links with more desirable characteristics (such as higher bandwidth) a lower cost. Accordingly, such links are usually selected when executing a routing algorithm.
A significant downside to this method of costing links is that the costs are static and, once defined/assigned to a link by an administrator, cannot be changed between users or between route determinations. Consequently, each user of the network is subject to these costs or, in other words, is subject to the importance the network administrator assigned to the varying characteristics of the network. However, not all services users wish to provision are the same. Accordingly, if given a choice, a user would typically assign different importance to the varying network characteristics (and thereby different link costs) depending on the service to be provisioned. As a result, the best route for a given service is typically not obtained. To get around this problem, a user needs to acquire detailed knowledge of the network to more particularly specify a desired route that meets the needs of the desired service.